As a valve opening/closing timing control apparatus, JP 2000-130118 A (Reference 1) discloses a technology in which a driven side rotator (a rotating member in Reference 1), which rotates along with a camshaft, and a driving side rotator (a rotation transmission member), which rotates along with a crankshaft, are provided, and a spool valve is provided coaxially with a connecting bolt (a mounting bolt), which connects and fixes the driven side rotator to the camshaft.
In the technology of Reference 1, a hydraulic oil is controlled by moving the spool valve in the axial direction using an actuator and a relative rotation phase between the driving side rotator and the driven side rotator is changed by the oil pressure of the hydraulic oil so as to arbitrarily set a valve opening/closing timing.
U.S. Pat. No. 6,363,896 (Reference 2) discloses a technology in which a driven side rotator (an inner element in Reference 2), which integrally rotates with a camshaft, and a driving side rotator (an outer element), which is driven by a crankshaft, are provided, and a spool is provided in a connecting bolt (a screw), which connects the driven side rotator to the camshaft.
In the technology of Reference 2, the supply and discharge of a fluid are controlled by moving the spool using an actuator so that a valve opening/closing timing is arbitrarily set by the fluid.
In addition, JP 2016-048043 A (Reference 3) discloses a technology in which a spool is provided in a connecting bolt, as in References 1 and 2, so that a hydraulic oil is controlled by moving the spool from the outside, and a sleeve is fitted onto the bolt.
In the technology of Reference 3, an introduction path, which supplies the hydraulic oil from an oil pump to the sleeve, is formed between the outer periphery of the connecting bolt and the inner periphery of the sleeve.
As described in References 1 to 3, since the configuration in which the spool is provided inside the connecting bolt may reduce the distance between the spool and the advanced angle chamber or the retarded angle chamber formed between the driving side rotator and the driven side rotator, the pressure loss of a flow path is reduced, thereby implementing an operation with good responsiveness.
However, in the configuration disclosed in References 1 and 2, since a flow path is formed in the connecting bolt or a member surrounding the connecting bolt, the flow path is easily complicated and increased in size.
On the other hand, in the configuration of Reference 3, since the hydraulic oil is discharged from the tip end side of the connecting bolt, the oil path is simplified, compared to that in References 1 and 2. However, in the configuration of Reference 3, since the introduction path, which supplies the hydraulic oil from the oil pump to the sleeve, is formed between the outer periphery of the connecting bolt and the inner periphery of the sleeve, a configuration of this portion is complicated.
In particular, in the configuration of Reference 3, although an oil path may be simplified by forming an introduction path using the sleeve, it is conceivable that pressure loss occurs in the introduction path, causing deterioration in responsiveness.
Thus, a need exists for a valve opening/closing timing control apparatus which is not susceptible to the drawback mentioned above.